1. Field of the Invention
This invention relates to a solenoid actuator for reciprocatingly driving a driven member by electromagnetic forces of two electromagnets.
2. Description of the Prior Art
Conventionally, a solenoid actuator of this kind is known which is applied to a valve-actuating mechanism for driving an intake or exhaust valve of an internal combustion engine to open and close the intake or exhaust valve. The valve-actuating mechanism has been proposed e.g. in Japanese Laid-Open Patent Publication (Kokai) No. 11-126715, which includes an armature connected to the intake or exhaust valve, and upper and lower electromagnets for vertically attracting the armature. The armature reciprocates between the upper and lower electromagnets whereby the intake or exhaust valve is driven to open or close. Further, in this kind of solenoid actuator which uses two electromagnets, to the coil of each electromagnet, two electric wires, hence a total of four electric wires, are connected from a lateral side, for supplying electric power thereto.
However, in the solenoid actuator described above, the valve-actuating mechanism of the internal combustion engine is limited in size, and hence space for wiring is also limited. It is not easy to carry out wiring work for the four electric wires within this limited space, and puts a large burden on workers. Further, the distance between the coils of the two electromagnets varies between a plurality of valve-actuating mechanism different in valve lift amount, which makes it impossible to apply the same electrical wiring to them. This increases the manufacturing costs of the engine.
It is an object of the invention to provide a solenoid actuator which is easy to carry out wiring work for coils thereof, and at the same time allows reduction of manufacturing costs through common application of a fixed wiring.
To attain the above object, the present invention provides a solenoid actuator supplied with electric power from a power source, for generating an electromagnetic force to drive a driven member such that the driven member performs reciprocating motion, comprising:
two electromagnets each having a coil and arranged such that the two electromagnets are opposed to each other and spaced from each other;
an armature connected to the driven member, and arranged between the two electromagnets, for performing reciprocating motion in accordance with energization and deenergization of the two electromagnets, to thereby drive the driven member such that the driven member performs the reciprocating motion;
two first metal connector elements connected to opposite ends of the coil of the each of the two electromagnets, and arranged such that the two first metal connector elements protrude outward from the each of the two electromagnets; and
a connector having four second metal connector elements electrically connectible to the power source, each two of the second metal connector elements being connected to the two first metal connector elements of the each of the two electromagnets, by effecting engagement between the each two of the second metal connector elements and the two first metal connector elements of the each of the two electromagnets in a direction parallel to a direction of the reciprocating motion of the armature.
According to this solenoid actuator, by effecting engagement between each two of the second metal connector elements of the connector and the two first metal connector elements of each of the two electromagnets, the first metal connector elements and the second metal connector elements corresponding thereto are connected to each other, whereby the coils of the electromagnets became electrically connected to the power source. In this case, the work of providing wiring for the coils of the two electromagnets can be carried out by causing the second metal connector elements of the connector to be engaged with the first metal connector elements of the electromagnets in a direction parallel to the direction of reciprocating motion of the armature, and the work for removing the wiring can be carried out only by effecting the disengagement between the first and second metal connector elements. This makes it possible to carry out the work for providing or removing the wiring even when there is limited space in a direction orthogonal to the direction of reciprocating motion of the armature. Further, since the engaging direction in which the connector is engaged with the electromagnets is parallel to the direction of reciprocating motion of the armature, by properly setting the length of each of the first and second connector metal elements along the engaging direction, and a distance between two pairs each consisting of the each two of the second metal connector elements, it is possible to accommodate variation in the distance between the two electromagnets among different solenoid actuators which are different in stroke of the driven member, whereby the connector of a single kind can be commonly applied to the different solenoid actuators. This makes it possible to reduce the manufacturing costs of the solenoid actuators. In the state of the solenoid actuator having the coils of the two electromagnets connected to the power source, as described above, in accordance with energization and deenergization of the two electromagnets, effected by causing and inhibiting supply of electric power from the power source to the electromagnets, the armature is caused to perform reciprocating motion, whereby the driven member is driven for the reciprocating motion.
Preferably, the each of the two electromagnets each includes a bobbin having the coil wound therearound, the two first metal connector elements being terminals arranged on the bobbin, and the connector is in a form of a rectangular column and has one end face, another end face opposite to the one end face, and a cut-away portion formed by cutting away a parallelepiped portion therefrom, the cut-away portion having a wall facing toward and parallel to the another end face, the four second metal connector elements being arranged in two first openings formed in the another end face of the connector and two second openings formed in the wall facing toward the another end face.
More preferably, the connector has four third openings formed in the one end face, the third openings having third metal connector elements respectively arranged therein , the third metal connector elements being electrically connected respectively to two of the four second metal connector elements arranged within the two first openings and two of the four second metal connector elements arranged within the two second openings, the third openings receiving terminals of a cable connected to the power source.
More preferably, the bobbin has a first brim having an end and a second brim, as well as a terminal portion projecting outward from the end of the first brim, and the terminals arranged on the bobbin projects perpendicularly from the terminal portion.